Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1991 Subaru Legacy LSi, AWDFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes
- Introduction
- Diagnosis & Testing
- Trouble Code Identification
- Specification Codes Identification
- Clearing Codes
- ECM Location
- Summary
- Diagnostic Code Charts
- Notes
- Basic Operation Of Self-Diagnostic System
- U-Mode Check
- Read Memory Mode
- D-Check Mode
- Clear Memory Mode
- Code 11: Crank Angle Sensor
- Code 12: Starter Switch
- Code 13: Cam Angle Sensor
- Codes 14, 15, 16 & 17: Fuel Injectors
- Code 21: Coolant (Water) Temperature Sensor
- Code 22: Knock Sensor
- Code 23: Airflow Meter Circuit
- Code 24: Air Control Valve
- Code 31: Throttle Position Sensor
- Code 32: Oxygen (O2) Sensor
- Code 33: Vehicle Speed Sensor
- Code 35: Canister Purge Control (CPC) Solenoid Valve
- Code 41: Air/Fuel Ratio Control System
- Code 42: Idle Switch
- Code 44: WASTEGATE Control Duty Solenoid Valve (Turbo)
- Code 45: Pressure Sensor Duty Solenoid (WASTEGATE Control)
- Code 45: Atmospheric Pressure Sensor (Non-Turbo)
- Code 49: Airflow Sensor
- Code 51: Neutral Safety Switch (Man. Trans.)
- Code 51: Inhibitor Switch (Auto. Trans.)
- Code 52: Parking Brake Switch (Auto. Trans.)
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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